We are just setting up a Build Controller at work for our projects. Our projects depend on the DLLs from another application that is installed on the end-user's machine. I don't want to install that application on the build server unless I have to. To that end, I have tried placing the DLLs that I need into the custom assemblies folder, but MSBuild is unable to locate them from there.
Can I use the custom assemblies folder for any DLLs that my project needs, or is it only for DLLs that the build process needs? (i.e. NUnit, StyleCop)
It is only for dll's that the build server needs.
For your dependencies you should package them as NuGet packages and have your projects take a dependency on that instead. This will allow these dll's to be resolved on any machine even if they don't have the bits installed.
You can use a UNC path as your nuget repository or ProGet which is free.